defensive strategies

[Armando]

what type of defensive moves can you do? i heard that you can knock an opponents ball out of the ring

[EricH]

what type of defensive moves can you do? i heard that you can knock an opponents ball out of the ring
...And it comes right back in. Do that too often, and the refs might call it.

In all seriousness, there is very little defense you can play this year. NASCAR style defense, maybe. Pin a trackball into a corner, maybe. Section 7 of the Game Manual has the rules on defense.

[Drwurm]

One thing you can do is block a hurdle if the opposing team no longer has control of the trackball being hurdled. This means that you could park a lift or an arm in front of a "shooter"-bot's trajectory and keep them from hurdling.

[jgannon]

Do that too often, and the refs might call it.
Do you see something in the manual that tells you that, or is it just a gut feeling? I'm pretty sure that it's a legitimate strategy, so long as you don't take possession of the ball. Maybe not particularly worthwhile, but legit.

[EricH]

One thing you can do is block a hurdle if the opposing team no longer has control of the trackball being hurdled. This means that you could park a lift or an arm in front of a "shooter"-bot's trajectory and keep them from hurdling.
Unless the ball has already crossed the plane. Then you just scored points for them.;) Before it crosses, and assuming that you don't cross, yeah, you could try it.

[Daniel_LaFleur]

what type of defensive moves can you do? i heard that you can knock an opponents ball out of the ring

Knocking the ball out of the ring is allowed, but might be considered un-GP by some refs ... so be careful with that one. Also be careful playing "keep away" with the opponents ball.

Knocking the opponents ball back across a line so that the opponent would have to go clockwise is a viable strategy.

Knocking the opponents ball off of the overpass at the end of a match is viable.

Pinning the opponents ball against a wall may work.

There is a shortest distance around the track that can be used to force your opponents to drive further.

There will be a decent amount of NASCAR style "rubbing" as the teams jocky for position ... enough so that I feel the required bumpers rulings are a good idea. I can see "bumping" to pass getting testy as well as teams "bump" corners of robots and turn them into the wall.

All-in-all I see some fun "interaction" between the robots.

Oh, and all of the above we can (and for some we will) do.

[EricH]

Do you see something in the manual that tells you that, or is it just a gut feeling? I'm pretty sure that it's a legitimate strategy, so long as you don't take possession of the ball. Maybe not particularly worthwhile, but legit.
Gut feeling. Also, a robot routinely doing this could take a hit from <S01>. (Something about the Trackball being good for human bowling...:D) Again, that's gut feeling.

Not to mention that the only places that you stand a chance of doing it without possessing are the same places trackballs are most likely to come in.

[Madison]

I think it'll all be about bumping with no intention to pass, rubbing, shoving and otherwise redirecting opponents as they travel around the track. I can't imagine for a second that everyone's going to play nicely as they drive around and around. There'll be as much pushing and shoving as any recent game.

[jgannon]

Knocking the ball out of the ring is allowed, but might be considered un-GP by some refs ... so be careful with that one. Also be careful playing "keep away" with the opponents ball.
The rules make no provisions for referees to make their own determinations with respect to a gameplay strategy being graciously professional... they merely enforce the rules given in the manual. People who spread this myth are discouraging teams from developing and attempting innovative ways of playing this game.

[IndySam]

A defensive bot can slowly herd an opponents ball preventing them from scoring. A couple of them could play a game of keep away. Could get ugly having teams jostling fort a ball.

[Drwurm]

I think it'll all be about bumping with no intention to pass, rubbing, shoving and otherwise redirecting opponents as they travel around the track. I can't imagine for a second that everyone's going to play nicely as they drive around and around. There'll be as much pushing and shoving as any recent game.

Every one of our experienced team members laughs when the animation says "Robots can signal the desire to pass by gently bumping." We hear "Ramming is legal this year, have fun!"

[JesseK]

When you do any of the strategies that have been mentioned above, you almost inherently take yourself out of any sort of scoring position. Sure, you could pin the ball against the wall and never move, or pin a backboard against the overpass so the opponent can never hurdle -- but the opponents have other ways to score, and you do not since you're sitting still.

At best, a bot built for a defensive strategy will be able to successfully use the strategies at spur-of-the-moment oppotunities. Still, a steady-scoring opponent will consistently outscore the defensive bot. The scores for the two alliances will be low, but I'm willing to bet that the "defensive" alliance's score will be the lower of the two almost every time.

[AdamHeard]

When you do any of the strategies that have been mentioned above, you almost inherently take yourself out of any sort of scoring position. Sure, you could pin the ball against the wall and never move, or pin a backboard against the overpass so the opponent can never hurdle -- but the opponents have other ways to score, and you do not since you're sitting still.

At best, a bot built for a defensive strategy will be able to successfully use the strategies at spur-of-the-moment oppotunities. Still, a steady-scoring opponent will consistently outscore the defensive bot. The scores for the two alliances will be low, but I'm willing to bet that the "defensive" alliance's score will be the lower of the two almost every time.

All of those strategies are losing propositions; scoring is where its at this year.

[IndySam]

When you do any of the strategies that have been mentioned above, you almost inherently take yourself out of any sort of scoring position. Sure, you could pin the ball against the wall and never move, or pin a backboard against the overpass so the opponent can never hurdle -- but the opponents have other ways to score, and you do not since you're sitting still.

At best, a bot built for a defensive strategy will be able to successfully use the strategies at spur-of-the-moment oppotunities. Still, a steady-scoring opponent will consistently outscore the defensive bot. The scores for the two alliances will be low, but I'm willing to bet that the "defensive" alliance's score will be the lower of the two almost every time.

Not if you have also have a solid scoring robot on your team or a real screamer that can burn the track.

I'm not saying that defense will be anything like it has in the last two years but an offensive team that is ignoring the possibilities is making a big mistake.

[Fred Sayre]

When you do any of the strategies that have been mentioned above, you almost inherently take yourself out of any sort of scoring position. Sure, you could pin the ball against the wall and never move, or pin a backboard against the overpass so the opponent can never hurdle -- but the opponents have other ways to score, and you do not since you're sitting still.

At best, a bot built for a defensive strategy will be able to successfully use the strategies at spur-of-the-moment oppotunities. Still, a steady-scoring opponent will consistently outscore the defensive bot. The scores for the two alliances will be low, but I'm willing to bet that the "defensive" alliance's score will be the lower of the two almost every time.

Strategically, trading machine for machine is a wash, and most teams will not shoot for this as a viable strategy. It marginalizes you into the masses (you are at maximum offsetting whatever machine you are defending against), making it hard for you to reach the top 8 positions, and this usually means that other teams will pick a scoring machine over yours.

Some situations arise though, where defensively one machine can effectively shut down, or slow the progress of multiple opponent machines or scoring strategies. When this is feasible some very tough decisions come into play, like subjective rule enforcement, and how to deal with subjective views on the GP of your strategy. Some games lend themselves to this, and others do not (I really wanted to see a bar defending robot in 2004, we tried but failed). Do I think this year you could win with a defending robot? Probably not. But many teams whose ball manipulation devices fail or fall short of being effective will default to some defensive strategies that while secondary functions, if the team is smart enough and talented enough to pull it off they may do very well in the competition - especially at weaker regionals where there might not even be a full list of 24 scoring machines. It is good to have a lot of this stuff available to your team if it becomes necessary.

In 2005 my old team could only get 1-2 tetras on the entire match, but we went 6-0 in Atlanta almost purely on defensive and offensive strategy and teamwork.

[Daniel_LaFleur]

All of those strategies are losing propositions; scoring is where its at this year.

Defensive strategies do not mean that the 'defensive robot' isn't scoring as well.

Consider 2 robots running around the field at 12+'/sec and 1 "gently bumps" the others corner and turns them into the wall. Thats a defensive play that will be seen again and again.

Or a robot shooting an opponents ball 10+' outside the playing field. it may take 15 seconds for the volunteers to corral the ball and get it back into play where that 'defensive bot' may have just run a lap and is ready to field the opponents ball again.

Or in the last 10 seconds of a match a 'defensive bot' knocking off 2 opponent track balls off the overpass stoping 24 points from being scored.

Are you sure you can outscore your opponent each and every match? I think defensive bots ... especially since there is less scoring objects than alliance robots ... will play a huge role in the game.

[Capt. Quirk]

I think it'll all be about bumping with no intention to pass, rubbing, shoving and otherwise redirecting opponents as they travel around the track. I can't imagine for a second that everyone's going to play nicely as they drive around and around. There'll be as much pushing and shoving as any recent game.


I think teams that use that strategy will end up with to many penalty points assed to themselves.

I think there is a great deal of strategic defenses (without giving up on scoring) , but not for teams with the "A" type personalities that are going for the big points. There are to many weaknesses for those "A" type teams, that rookie teams (and the TrackBall) could easily spoil.

[Madison]

I think teams that use that strategy will end up with to many penalty points assed to themselves.

I think there is a great deal of strategic defenses (without giving up on scoring) , but not for teams with the "A" type personalities that are going for the big points. There are to many weaknesses for those "A" type teams, that rookie teams (and the TrackBall) could easily spoil.

Penalties based upon what?

[Ericgehrken]

This is the year for the best defense being an amazing offense. Specializing in defense is not a good idea. Defense doesn't win matches. It helps but the ideal alliance will need three amazing scorers that are not going to be interfered with much by ramming. Some NASCAR style defense will be played such as ramming and bumping corners. We might see a bump and run move for position on the field.

[midway78224]

we plan to knock off opps. balls all during the game and it works really well

[Capt. Quirk]

This is the year for the best defense being an amazing offense. Specializing in defense is not a good idea. Defense doesn't win matches. It helps but the ideal alliance will need three amazing scorers that are not going to be interfered with much by ramming. Some NASCAR style defense will be played such as ramming and bumping corners. We might see a bump and run move for position on the field.

What is the 3rd scoring Bot going to be doing?, while the other alliance partners have the 2 trackballs. Waiting to take it's turn, isn't scoring any points and that will happen every lap to every alliance partner.

[Swampdude]

I think defense as well as offense will be a part of every lap you make. If my alliance knows team x can hurdle, then that team can expect a poke at the ball thier trying to collect each time one of my alliance partners passes them, which is 3. Not to mention, they have 2 alliance partners going by, and 4 balls. So hopefully you can all imagine how hard it's going to be to get one of those balls up off the ground to hurdle it. Herding, and "de-herding" quickly is the trick.

[IndySam]

There is nothing in the rules that says a defending robot can't make it difficult for an opposing robot to pick up the ball as long as they don't block the track or pin the opponent.

Think about a robot that stops a bot from picking up the ball and then shoves them across the line so they can't come back.

I think there will be a lot more defense than some people are thinking.

[Capt. Quirk]

Penalties based upon what?



<G37> "In all cases involving ROBOT-to-ROBOT contact, the TEAM may
receive a PENALTY and/or their ROBOT may be disqualified if the interaction is
inappropriate or excessive."

I believe they are try to get away from last years bumping & shoving

[EricH]

<G37> "In all cases involving ROBOT-to-ROBOT contact, the TEAM may
receive a PENALTY and/or their ROBOT may be disqualified if the interaction is
inappropriate or excessive."

I believe they are try to get away from last years bumping & shovingI believe that was in last year's manual also. (I don't have a copy available at this time.) Penalties were rare.

[Vikesrock]

<G37> "In all cases involving ROBOT-to-ROBOT contact, the TEAM may
receive a PENALTY and/or their ROBOT may be disqualified if the interaction is
inappropriate or excessive."

I believe they are try to get away from last years bumping & shoving

A partial quote of this rule is extremely misleading. Here is the entire rule (emphasis mine)

<G37> ROBOT to ROBOT Interaction - Strategies aimed solely at the destruction, damage, tipping
over, or entanglement of ROBOTS are not in the spirit of the FIRST Robotics Competition
and are not allowed. In all cases involving ROBOT-to-ROBOT contact, the TEAM may
receive a PENALTY and/or their ROBOT may be disqualified if the interaction is
inappropriate or excessive. However, it is noted that FIRST Overdrive is a highly interactive
game. Robust construction of ROBOTS will be very important in this high-speed
competition. ROBOTS should be designed to withstand the high-speed contact that will
occur during the MATCH. Appropriate contact is allowed under the following guidelines:
a. High speed accidental collisions are likely to occur during the MATCH, and are an
expected part of the game. However, high-speed intentional ramming is not acceptable
and will be penalized.
b. Contact within the BUMPER ZONE is generally acceptable.
c. Contact outside of the BUMPER ZONE is generally not acceptable, and will result in a
PENALTY. The offending ROBOT may be disqualified from the MATCH if the offense is
particularly egregious or if it results in substantial damage to another ROBOT. However,
incidental contact outside of the BUMPER ZONE will not be penalized.
d. If a ROBOT extends outside of the perimeter of the STANDARD BUMPERS (the
perimeter of the bumpers is the polygon defined by the outermost corners of each
STANDARD BUMPER segment), it is responsible for the extension's contact with other
ROBOTS. The ROBOT must not use the extension to contact other ROBOTS outside of
the BUMPER ZONE. Likewise, other ROBOTS will not be responsible for contact with
the extension outside of the BUMPER ZONE. Again, incidental contact will not be
penalized.
e. Extension to extension contact between two ROBOTS with appendages outside the
ROBOT perimeter of the STANDARD BUMPERS will generally not be penalized.
f. Contact with a tilted ROBOT outside the BUMPER ZONE (particularly if resulting from
contact within the BUMPER ZONE) will generally be considered incidental contact.
g. A ROBOT may not attach to and/or climb onto a ROBOT on an opposing ALLIANCE
(doing so will be interpreted as an attempt to damage an opposing ROBOT, and will be
penalized as such).
h. Use of any sloped or angled feature of the ROBOT as a wedge to overturn an opposing
ROBOT is explicitly prohibited, and will be assessed as a violation of Rule <R19>.

Any robot pushing or shoving will almost certainly be doing so from within the bumper zone which would appear to be entirely legal.

[Capt. Quirk]

I sincerly hope it won't be all about pushing and shoving, there isn't a central goal like the last two years. So there no reason to try and push some one away. They seemed to give the Hurdling robots adequate penalty protection in the rules.

If it does come down to that, I believe that it's a counter-productive strategy for both alliances.

[Armando]

I was wondering because our arm failed in last year's competition, and we had to resort to defensive moves. our robot was rather light so the best we could do was get between them and the rack, preventing their arms to reach the rack. this year we might have to transition to defense again, if all else fails

[David Brinza]

If your opponent has good hurdling robots, playing "keep away" can be an effective defensive strategy. As long as you don't POSSESS the opponent's trackball, you can maneuver it away from their robots. Even herding the opponent's ball across their finish line to give them 2 points is better than allowing them to score 8. Once their ball crosses the line, it will take time for the ball to get back into the home stretch. A decent defensive robot can really slow down the opponent's scoring machines.

[Madison]

I sincerly hope it won't be all about pushing and shoving, there isn't a central goal like the last two years. So there no reason to try and push some one away. They seemed to give the Hurdling robots adequate penalty protection in the rules.

If it does come down to that, I believe that it's a counter-productive strategy for both alliances.

As some others have already mentioned, there are lots of reasons to push, shove, redirect or otherwise inconvenience your opponents in this game. Sure, they've made things seem on the surface that even the most basic of robots can score points by driving in circles and contribute to an alliance, but I'm confident that reality will quickly render that an ineffective strategy.

If one alliance contains a scoring machine -- hurdling or otherwise -- that is markedly more effective than those machines on the other alliance, using a low-functioning or ineffectual machine to mitigate the effectiveness of the superior machine is an absolutely viable strategy. If the effective machine typically hurdles four times in one match and you hold them to three hurdles, you've significantly decreased their contribution to the overall match score and their contribution to the alliance. By doing that, it might mean you've made a few less laps than you might've otherwise, but as long as you prevent them from scoring more points than you could've earned in the same time frame, you're going to come out on top.

[Josh Drake]

I think defense as well as offense will be a part of every lap you make. If my alliance knows team x can hurdle, then that team can expect a poke at the ball thier trying to collect each time one of my alliance partners passes them, which is 3. Not to mention, they have 2 alliance partners going by, and 4 balls. So hopefully you can all imagine how hard it's going to be to get one of those balls up off the ground to hurdle it. Herding, and "de-herding" quickly is the trick.

I agree, if you want to hurdle, you need to be able to pick it up quickly and be in the process of hurdling, so the defense will subside.

[Rick TYler]

I was surprised not to see this in any of the Regionals I've witnessed:

Setting: Red alliance has two great hurdlers and a speedy lapper. Blue has two hurdlers and a third bot that can herd and descore, but has a marginally useful arm that might be able to hurdle once a match if no one nudges them.

Why wouldn't blue have their third robot simply POSSESS a red ball for the entire match? The way the rules are written, this would cost blue a single 10-point penalty, but would deprive red of 30-50 hurdling points. Seems like a no-brainer role for a weak third bot in an alliance -- the red hurdlers play with only one ball between them, but the blues get two. What am I missing?

[Cowmankoza]

I was surprised not to see this in any of the Regionals I've witnessed:

Setting: Red alliance has two great hurdlers and a speedy lapper. Blue has two hurdlers and a third bot that can herd and descore, but has a marginally useful arm that might be able to hurdle once a match if no one nudges them.

Why wouldn't blue have their third robot simply POSSESS a red ball for the entire match? The way the rules are written, this would cost blue a single 10-point penalty, but would deprive red of 30-50 hurdling points. Seems like a no-brainer role for a weak third bot in an alliance -- the red hurdlers play with only one ball between them, but the blues get two. What am I missing?

The idea that your missing is that continually violating a rule can earn your team a yellow card or potentially a DQ

[ALIBI]

While you may not possess your opponents tracball, you can wedge it between yourself and the walls, especially in the corners. Works well. I expect to see teams doing that over and over in Atlanta.

[Rick TYler]

The idea that your missing is that continually violating a rule can earn your team a yellow card or potentially a DQ

There are six rules that specifically state that repeated violations can lead to disqualification. G29 is not one of them.

Interestingly, in "The Game" rules, rev G, the term "YELLOW CARD" is used in <G41> but not in any other rule. The YELLOW CARD and RED CARD rules appear in <T05>: "The Head Referee may assign a YELLOW CARD as a warning of egregious ROBOT or team member behavior." There is no definition of "egregious" but I would argue that violation of a game rule is not in and of itself egregious. Several robots in Seattle committed at least a dozen G22 errors (one robot managed four in a single match), and not one of them was yellow-carded. In the rules, only <G41> is specifically eligible for a yellow card for repeated violations. If the GDC took time to single out <G41>, why wouldn't they mention other rules?

As it turns out, I'd be in favor of adding <G29> to the "yellow card" rules with <G41>, but the question here was, has anyone tried it?

[Vikesrock]

There are six rules that specifically state that repeated violations can lead to disqualification. G29 is not one of them.

Interestingly, in "The Game" rules, rev G, the term "YELLOW CARD" is used in <G41> but not in any other rule. The YELLOW CARD and RED CARD rules appear in <T05>: "The Head Referee may assign a YELLOW CARD as a warning of egregious ROBOT or team member behavior." There is no definition of "egregious" but I would argue that violation of a game rule is not in and of itself egregious. Several robots in Seattle committed at least a dozen G22 errors (one robot managed four in a single match), and not one of them was yellow-carded. In the rules, only <G41> is specifically eligible for a yellow card for repeated violations. If the GDC took time to single out <G41>, why wouldn't they mention other rules?

As it turns out, I'd be in favor of adding <G29> to the "yellow card" rules with <G41>, but the question here was, has anyone tried it?

As much as I hate to suggest reffing by intent, I would say that possessing an opponents trackball for the entire match obviously shows that it was done intentionally which, to me, constitutes egregious behavior.

[Madison]

There're all sorts of situations wherein one may intentionally violate the rules and draw a penalty but come out ahead. I have not seen this sort of behavior receive a yellow card.

In Seattle, we intentionally violated G22 once and almost again a second time.

[Rick TYler]

There're all sorts of situations wherein one may intentionally violate the rules and draw a penalty but come out ahead. I have not seen this sort of behavior receive a yellow card.

In Seattle, we intentionally violated G22 one and almost again a second time.

And if I remember correctly, one of your alliance partners risked a G22 to nudge you upright in a match. If not you, it was someone else -- watching every single match (about 100 at Seattle) converts some memories to a blur...

Anyway, grabbing an opponent's trackball and grappling it for two minutes at the cost of a 10-point penalty would surely incur the wrath of the officials -- if not immediately, then eventually. It's like 190's spinning tower, it's just such an obvious perversion of the rules that someone is going to look for a problem with it.

Taking a foul on purpose to further the strategic goal of your team is a tried-and-true tactic in sports. Hmm. I wonder if violating <G29> would draw a yellow flag.

[EricH]

In Seattle, we intentionally violated G22 once and almost again a second time.Was a partner stuck on the overpass?

[Madison]

Was a partner stuck on the overpass?

Yes -- we violated <G22> when helping someone stuck in the overpass.

The second instance would've involved deliberately breaking <G22> to place a bonus ball onto the overpass, but we ran out of time.

[d.courtney]

Why wouldn't blue have their third robot simply POSSESS a red ball for the entire match? The way the rules are written, this would cost blue a single 10-point penalty, but would deprive red of 30-50 hurdling points. Seems like a no-brainer role for a weak third bot in an alliance -- the red hurdlers play with only one ball between them, but the blues get two. What am I missing?
Why not block the other ball from play while your at it? I honestly would love to see the refs reaction to someone in procession of an opponents ball while blocking the teams from getting the other one which is in a corner, though thats just asking to be yellow carded.

[danshaffer]

Why not block the other ball from play while your at it? I honestly would love to see the refs reaction to someone in procession of an opponents ball while blocking the teams from getting the other one which is in a corner, though thats just asking to be yellow carded.

you'd still have to leave a passing lane, otherwise you could be moved for a bump to pass...

[dtengineering]

I was surprised not to see this in any of the Regionals I've witnessed:

Setting: Red alliance has two great hurdlers and a speedy lapper. Blue has two hurdlers and a third bot that can herd and descore, but has a marginally useful arm that might be able to hurdle once a match if no one nudges them.

Why wouldn't blue have their third robot simply POSSESS a red ball for the entire match? The way the rules are written, this would cost blue a single 10-point penalty, but would deprive red of 30-50 hurdling points. Seems like a no-brainer role for a weak third bot in an alliance -- the red hurdlers play with only one ball between them, but the blues get two. What am I missing?

This strategy could be interpreted a couple different ways. One is that they only get one ten point penalty. However looking at the rule:

<G29> POSSESSING Opponent’s TRACKBALLS - ROBOTS may not be in the POSSESSION of a TRACKBALL belonging to an opposing ALLIANCE. A PENALTY will be assigned for each violation....

and the definition of POSSESSION:

POSSESSION: Controlling the position and movement of a TRACKBALL while the TRACKBALL is supported or captured by an ALLIANCE shall be considered POSSESSION of the TRACKBALL.

could also lead one to assume that each change in position or movement of the robot possessing the opponent's trackball could be a new violation and a new penalty. (What happens if they take possession and hit "disable"?) I suspect what would happen, however, would be that after assessing the first penalty, the ref would instruct the possessing team to release the opponents' trackball, and if they failed to proceed to do so in a timely fashion they would continue to receive penalties.

Interestingly our team DID take possession of an opponent's trackball in Portland, entirely by mistake. The rest of the drive team was yelling at our (normally very calm and collected and "on the ball") driver... "NO NO WRONG COLOUR" but he grabbed the ball anyway. Fortunately our launch operator immediately hit the "fire" button (which is seperate from our launcher's charge button... the fire just gives the ball a little kick if the system is not charged) and the ball popped free before the refs noticed.

The main reason we haven't seen this strategy, though, in my opinion is because most teams have bought in to the concept that this game is supposed to be about scoring and the teams that are capable of posessing a ball want to go score some points with it!

Jason

[Rick TYler]

Interestingly our team DID take possession of an opponent's trackball in Portland, entirely by mistake. The rest of the drive team was yelling at our (normally very calm and collected and "on the ball") driver... "NO NO WRONG COLOUR" but he grabbed the ball anyway.

Well, no wonder he wasn't dumping the ball. They were yelling "colour" instead of "color" and the tournament was in the USA.

[daf]

I'm glad this thread came back up. I've been wondering how defense could be played after seeing the lack of it in just about every regional I've witnessed.

It looks to me as though defense itself is not a very good strategy unless it is "on the move" such as knocking an opponent trackball clockwise etc. But the best defense which I unfortunately have yet to see is what everyone else has already brought up: just taking an opponent trackball. How much harder would it be just to pin it in a corner rather than possessing it? You accomplish the same thing without receiving a penalty. The two best alliance members could just rack up the points while the third bot can be put on the task of pinning an opponent trackball and taking it out of the game. It seems to me like shutting down your opponents opportunity to score without even getting penalized does more for your alliance than just goin around the tack does. If you could get your hands on an opponent trackball early in the match, you take out half of your opponents points. I really want to see this strategy used in Atlanta (just not against my team:D ). My only fear is that if this strategy is used to often and the game turns into one on one trackballs, the refs would do something to counteract this. I don't think this strategy is what first was aiming for when designing the game (but I do like it a lot). If it's overused, I bet a rule will be made along the lines of "you can't pin an opponent trackball for more than 6 seconds" or something like that.

[XXShadowXX]

this years defense can be played like thus, my team played defense during the semi finals in west michigan ill post the links.

http://www.thebluealliance.net/tbatv/match.php?matchid=8664
http://www.thebluealliance.net/tbatv/match.php?matchid=8711

We herded our oppents trackballs around the track (gives them 2 points, but which would you rather have them score 2 or 8 points)? Basically you play a long game of keep away, don't let your oppent caputure the trackball.
You can't see the finals which i believe that we were at our best in stopping of the oppents scoring.

[Grant Cox]

this years defense can be played like thus, my team played defense during the semi finals in west michigan ill post the links.

http://www.thebluealliance.net/tbatv/match.php?matchid=8664
http://www.thebluealliance.net/tbatv/match.php?matchid=8711

We herded our oppents trackballs around the track (gives them 2 points, but which would you rather have them score 2 or 8 points)? Basically you play a long game of keep away, don't let your oppent caputure the trackball.
You can't see the finals which i believe that we were at our best in stopping of the oppents scoring.
I actually came in here just to commend your team for that. You effectively shut down some of the most effective hurdlers there.

For those who weren't at WMR, team 2604 put on what was, without a doubt, one of the best defensive demonstrations this game has seen so far. They constantly herded the opponent's trackball, corralling it in a corner (and even pushing it out of the field once or twice). Their speed and skill at controlling the ball shut down the opposing hurdler that was trying to use it. My friends sitting around me were constantly yelling "there is no way that's legal!!" while I just smiled and told them "it's not only legal, it's an incredible strategy."

[danshaffer]

I'm glad this thread came back up. I've been wondering how defense could be played after seeing the lack of it in just about every regional I've witnessed.

It looks to me as though defense itself is not a very good strategy unless it is "on the move" such as knocking an opponent trackball clockwise etc. But the best defense which I unfortunately have yet to see is what everyone else has already brought up: just taking an opponent trackball. How much harder would it be just to pin it in a corner rather than possessing it? You accomplish the same thing without receiving a penalty. The two best alliance members could just rack up the points while the third bot can be put on the task of pinning an opponent trackball and taking it out of the game. It seems to me like shutting down your opponents opportunity to score without even getting penalized does more for your alliance than just goin around the tack does. If you could get your hands on an opponent trackball early in the match, you take out half of your opponents points. I really want to see this strategy used in Atlanta (just not against my team:D ). My only fear is that if this strategy is used to often and the game turns into one on one trackballs, the refs would do something to counteract this. I don't think this strategy is what first was aiming for when designing the game (but I do like it a lot). If it's overused, I bet a rule will be made along the lines of "you can't pin an opponent trackball for more than 6 seconds" or something like that.

just watch the finals from silicon valley, specifically the 8bot (it's a white triangle)

[daf]

can u post a link? there are no vids of it on bluealliance

[waialua359]

that strategy is actually something that many teams have talked about and have tried doing. Doing it with success is another story.
That is what we believed all along was the "best" legal strategy!

Here's food for thought?? Has anyone seen team 224's robot?
They have the most unique way that I've seen in controlled herding of the ball. I wonder if its legal in doing the same for the opponents ball.
Once they get a ball, you cant steal it from them. Technically, they dont grab the ball at all.

I'd like to hear comments from the GDC on the legality of that. If it is, they could potentially be the best at defense at CMP, hands down!

[NOV8R]

Our robot was designed from the begining to pin the opposition's ball against the wall. By designed I mean special vertical aluminum tubes (24 inch high) that pin the ball against the wall. We also have a way of descoring the ball during hybird and the end of the game, but our primary strategy is keeping the ball from good opposition hurdlers. As regionals have progressed we're more encouraged we have a viable way of playing defense. So how well has it worked for us? We'll tell you this weekend. Our regional (Denver) is this week.

[Vikesrock]

that strategy is actually something that many teams have talked about and have tried doing. Doing it with success is another story.
That is what we believed all along was the "best" legal strategy!

Here's food for thought?? Has anyone seen team 224's robot?
They have the most unique way that I've seen in controlled herding of the ball. I wonder if its legal in doing the same for the opponents ball.
Once they get a ball, you cant steal it from them. Technically, they dont grab the ball at all.

I'd like to hear comments from the GDC on the legality of that. If it is, they could potentially be the best at defense at CMP, hands down!


I can't tell exactly how well the ball is held from the videos or picture on TBA but if you can't take it away then they likely meet the definition of possession (via "captured"):
POSSESSION: Controlling the position and movement of a TRACKBALL while the TRACKBALL is
supported or captured by an ALLIANCE shall be considered POSSESSION of the TRACKBALL. A
TRACKBALL shall be considered “supported” by a ROBOT if in the estimation of a reasonably
astute observer the majority of the weight of the TRACKBALL is being borne by the ROBOT. A
TRACKBALL shall be considered “captured” by a ROBOT if, as the ROBOT moves or changes
orientation (e.g. backs up or spins in place), the TRACKBALL remains in approximately the same
position relative to the ROBOT. Both the “supported” and “captured” conditions include the case
where the TRACKBALL is also in contact with the floor.

[JB987]

How hard would it be for an official to rule a "pinned" ball as a captured ball" and cite this?...POSSESSION: Controlling the position and movement of a TRACKBALL while the TRACKBALL is supported or captured by an ALLIANCE shall be considered POSSESSION of the TRACKBALL.
Aren't you indeed controlling the position of the ball and isn't it "captured" if your robot pins the ball between it and the wall such that another bot can not make contact with it?

[Vikesrock]

How hard would it be for an official to rule a "pinned" ball as a captured ball" and cite this?...POSSESSION: Controlling the position and movement of a TRACKBALL while the TRACKBALL is supported or captured by an ALLIANCE shall be considered POSSESSION of the TRACKBALL.
Aren't you indeed controlling the position of the ball and isn't it "captured" if your robot pins the ball between it and the wall such that another bot can not make contact with it?

The rule goes on to define captured. It's definition of captured requires the ball to maintain the same position relative to the robot if the robot were to move. If you are pinning the ball against the wall it will not keep the same relative position to the robot when you move so it should not be considered possession.

[Guy Davidson]

Joe, as per the manual in the Game section:

A TRACKBALL shall be considered “captured” by a ROBOT if, as the ROBOT moves or changes orientation (e.g. backs up or spins in place), the TRACKBALL remains in approximately the same position relative to the ROBOT. Both the “supported” and “captured” conditions include the case where the TRACKBALL is also in contact with the floor.

As a result, pinning the ball between a robot and a wall is perfectly legal, prodvided there is a lane around the pinning robot (otherwise it is impeding) and that said robot is not supporting the weight of the ball.

[JB987]

The rule goes on to define captured. It's definition of captured requires the ball to maintain the same position relative to the robot if the robot were to move. If you are pinning the ball against the wall it will not keep the same relative position to the robot when you move so it should not be considered possession.

I see this definition from the beginning of the Game Section now...so technically then a pinned ball is not captured. I guess one solution in this situation would be for robots with high torque low end transmissions to legally push the pinning bot out of the way to expose the ball? So now we bring back some of previous years pushing matches...(all within the bumper zone of course). And with fewer hurdles, then auto becomes an even bigger part of the game.

[Cory]

I must admit, I find the pinned ball in the corner strategy exceedingly boring. Totally within the rules, but not at all entertaining. I don't claim to be a mind reader, but I can't imagine the GDC wished for teams to just sit there and block access to the balls for the entire match.

For all practical purposes, if a team knows what they are doing, they are effectively possessing the ball, and totally keeping the other alliance from having any chance whatsoever to be able to get their own ball.

On the other hand, I have been very impressed by some of the herding defense I have seen. Some teams are very good at pushing opposing balls around, and keeping them just out of reach of the offensive team. I think this is sound strategy, and quite entertaining (though frustrating if you are on the receiving end). Defense like this is smart, safe, and commendable.

[Travis Hoffman]

I must admit, I find the pinned ball in the corner strategy exceedingly boring. Totally within the rules, but not at all entertaining. I don't claim to be a mind reader, but I can't imagine the GDC wished for teams to just sit there and block access to the balls for the entire match.


Ah the subtle psychological tactics of the pro-offensive. Cory, you sly dog. ;)

If the GDC felt so strongly that they didn't want to see it as part of the game, it wouldn't be in the rules. I half expect a Team Update now that I said that.

It is NOT our responsibility to judge the GDC's intent. It is the GDC's responsibility to craft the rules such that all doubt is removed.

You guys play YOUR legal game; boring or otherwise, if it's effective, that's all that matters. Don't let other teams dissuade you from YOUR own gameplan via suggestive peer pressure!

I suggest treating a trackball as a "stack o' bins" from 2003, and protecting it thusly - by parking the trackball against the field border and patrolling an arc around it, keeping your bot between the ball and would be acquirers. Then there is no active pinning of the ball, and there can be no doubt of the legality of your defensive maneuver. If it looks as if you're going to lose perimeter integrity, poke the ball clockwise into another quadrant - preferably into the opposing homestretch. Not only do the assailants have to waste time completing a lap to get the ball, they then have to do ANOTHER lap to reestablish the trackball as a scoreable object.

[Brandon Holley]

I suggest treating a trackball as a "stack o' bins" from 2003, and protecting it thusly - by parking the trackball against the field border and patrolling an arc around it, keeping your bot between the ball and would be acquirers. Then there is no active pinning of the ball, and there can be no doubt of the legality of your defensive maneuver. If it looks as if you're going to lose perimeter integrity, poke the ball clockwise into another quadrant - preferably into the opposing homestretch. Not only do the assailants have to waste time completing a lap to get the ball, they then have to do ANOTHER lap to reestablish the trackball as a scoreable object.

There is no doubt now that it is a viable strategy.

The rule says the trackball is considered to be "captured" if as the robot moves, the trackball position stays the same relative to the robot. Pinning it against a wall does not do that.


I agree with cory too on this one. Its very boring to watch. Whether its viable or not is a different story, but it is boring. The herding defense is very fun to watch, and in my eyes the better way to go.

[Qbranch]

A defensive bot can slowly herd an opponents ball preventing them from scoring. A couple of them could play a game of keep away. Could get ugly having teams jostling fort a ball.

We've seen that one, especially at buckeye. All you have to do is cut them off new-yorker style... (aka get just a little in front of them and make a hard right into their path)... and you get your ball back. :D

-q

[Travis Hoffman]

We've seen that one, especially at buckeye. All you have to do is cut them off new-yorker style... (aka get just a little in front of them and make a hard right into their path)... and you get your ball back. :D

-q

Tony Stewart-style?

Tradin' foam!

[NOV8R]

This discussion reminds me of one of my favorite cartoons where there are two settlers under indian attack crouched under a wagon with a burning arrow in the side. The caption on the cartoon is one settler asking the other "Are they (the indians) allowed to do that?" Good defense is not boring to those of us who like to come up with innovative ways to do it.

[Brandon Holley]

This discussion reminds me of one of my favorite cartoons where there are two settlers under indian attack crouched under a wagon with a burning arrow in the side. The caption on the cartoon is one settler asking the other "Are they (the indians) allowed to do that?" Good defense is not boring to those of us who like to come up with innovative ways to do it.

honestly, and please dont take this the wrong way...I personally dont consider pinning a ball against a piece of diamond plate for 2 minutes innovative. Making a robot that can knock off both balls and hit 5 lines is innovative, or makng a robot thats faster than everyone, but still controllable, thats innovative. Making a catapult that can throw the ball diagonally across the field is innovative. I dont see pinning a ball against a wall innovative.

My 2 cents..

[NOV8R]

How the ball is pinned can be innovative. That's just one part of our overall strategy and play book. We can also take the ball off the overpass on the move and make 2-3 lines during hybird. Depending on the opposition we can just run laps and herd as well in teleoperated. One thing for sure we won't do is roll over and let the opposition hurdle at will. If you want to see those kind of matches lobby the GDC to only have one robot on the field at a time. In addition to a retired engineer I'm also an ex Air Force fighter pilot and learned a long time ago the value of playing assertive (not agressive) defense.

[XXShadowXX]

This discussion reminds me of one of my favorite cartoons where there are two settlers under indian attack crouched under a wagon with a burning arrow in the side. The caption on the cartoon is one settler asking the other "Are they (the indians) allowed to do that?" Good defense is not boring to those of us who like to come up with innovative ways to do it.

only problem is most teams can change defensive plans, in match, hard to change hurdling idea's in match

defense is one bot, when you can protect 2 oppent trackballs, defeating defense becomes the whole alliance's problem

[Qbranch]

This is starting to sound like the infamous Intentionally Blocking in Hybrid (http://www.chiefdelphi.com/forums/showthread.php?t=65301) thread.

You can't tell defensive players they can't play defense. Many offensive players still play defense while scoring offensive points (can't speak for anyone else's driving strategy, but for us, if we can wap the ball away from you while we're carrying a ball, we'll do it) and even purely defensive players make life interesting for purly (or partly) offensive players.

Again, as in the thread I mentioned previously, there's almost always another way around something such as defense... like... you could cut off the robot taking the ball from you... if a robot has just placed a ball on top of the overpass, you want to knock it off, and they wont move... go around the other side of the rack and knock it off from that side...

Think of it like Interpretive Driving. :rolleyes:

-q

[rick.oliver]

... go around the other side of the rack and knock it off from that side...

-q

If I understand your suggestion, that will draw you a ten point penalty.

[jayjaywalker3]

Our robot was designed from the begining to pin the opposition's ball against the wall. By designed I mean special vertical aluminum tubes (24 inch high) that pin the ball against the wall. We also have a way of descoring the ball during hybird and the end of the game, but our primary strategy is keeping the ball from good opposition hurdlers. As regionals have progressed we're more encouraged we have a viable way of playing defense. So how well has it worked for us? We'll tell you this weekend. Our regional (Denver) is this week.

So? How did your regional go?

[Brandon Holley]

How the ball is pinned can be innovative. That's just one part of our overall strategy and play book. We can also take the ball off the overpass on the move and make 2-3 lines during hybird. Depending on the opposition we can just run laps and herd as well in teleoperated. One thing for sure we won't do is roll over and let the opposition hurdle at will. If you want to see those kind of matches lobby the GDC to only have one robot on the field at a time. In addition to a retired engineer I'm also an ex Air Force fighter pilot and learned a long time ago the value of playing assertive (not agressive) defense.

"Rolling over" and letting the opposition hurdle at will is almost certainly something no alliance wants to do.

And I guess we are going to have to agree to disagree on the front that pinning a ball is innovative. I frankly, cannot see it as innovative.

Believe me when I say I know the value of defense (I am a "maverick" from the mid-atlantic/new england states). When our arm cracked off in the quarters of boston, the first thing we did was start playing defense by sitting in front of the other teams balls. However, I did not think that was an innovative strategy. Being able to fire diagonally across the field to hurdle, I see that as innovative.

Like I said, it appears we have different views on what is "innovative".

[JudyVandy]

Hey, guys, check out Philly's Finals Matches!

[petek]

I must admit, I find the pinned ball in the corner strategy exceedingly boring.I take it you didn't see the finals in Philly. Chuck played this card several times to slow down the #1 alliance and allow the slightly slower hurdling 341 and 365 to beat 103 and 272, but those three matches were anything but boring! There's nothing boring about a 114:114 tie being broken by a ball rolling across the line right after the buzzer.

[Rick TYler]

I'm still willing to pay up to six Krispy Kreme donuts to the first team that picks up and possesses an opponent's track ball for an entire match. I want to see how referees would rule on this...

(Maybe someone could try it during practice at New York this week just to get a ruling?)

[David Brinza]

I'm still willing to pay up to six Krispy Kreme donuts to the first team that picks up and possesses an opponent's track ball for an entire match. I want to see how referees would rule on this...

(Maybe someone could try it during practice at New York this week just to get a ruling?)
One might argue that this is "egregious" behavior that could earn a yellow card and subsequently, a red card or DQ. I wouldn't risk it.

[Corey Balint]

I'm still willing to pay up to six Krispy Kreme donuts to the first team that picks up and possesses an opponent's track ball for an entire match. I want to see how referees would rule on this...

(Maybe someone could try it during practice at New York this week just to get a ruling?)
An alliance I was helping at UTC discussed it this year. We had a friend, who didn't identify with any team, go up and ask 4 refs what they would say, including the head ref. One ref said DQ. Another said penalty once, and thats it (no warnings). 2 said that there would be a penalty and if they were to hold on to it for the whole match a warning (possibly a yellow card). 3 of the 4 said DQ if you were to do it more than once.

The alliance I was working with thought this would be a great strategy and would surely win each match that this was done in.

[Brdn666]

Im the driver for team 2604 and when we tried our D strat, we moved the ball and it was the most exciting part of the WMR for me.